Officials in Switzerland as well as reportedly the U.K. are looking into hundreds of millions in restructured debt deals carried out by Credit Suisse and Russian bank VTB for debt-plagued Mozambique.

More than $1 billion in previously undisclosed debt deals for the sub-Saharan country, which has pinned its economic hopes of liquified natural gas, have been revealed recently. The heavy debt burden has brought Mozambique, rated «distressed» by ratings agency Standard & Poor's, to the brink of defaulting.

Credit Suisse and VTB ran several debt deals for Mozambique's state-owned companies, including a $850 million one to buy a tuna-fishing fleet. Much of the tuna fleet proceeds were diverted to the military, it has since revealed.

The bond deals may have violated regulations over how much investors must be informed about debt restructuring, the «Wall Street Journal» has reported. Both Credit Suisse and VTB, which is Russian, appear to have used their U.K. operations for the bond deals.

The deals include $1.16 billion in loans for military equipment and to build a shipyard and $850 million in bonds for a tuna-fishing fleet.